Human papillomavirus (HPV) is the most common sexually transmitted infection (STI) in the United States (US), and infections can cause a range of adverse health outcomes among females, including several types of cancer (e.g., cervical cancer) and anogenital warts. Women are at risk for HPV infection regardless of their sexual orientation since HPV can be transmitted between female sexual partners, and many sexual minority women (i.e., women with a history of sex with women or who identify as non-heterosexual) have current or past male sexual partners from whom they could have acquired HPV. Our long-term goal is to develop and test an HPV and cervical cancer prevention intervention for sexual minority women, and our preliminary research shows that a preferred intervention component is targeted information about the prevalence HPV infection among sexual minority women. However, epidemiological data on HPV infection (genital and oral) among this population are currently lacking. Further, to date, no research has examined how the prevalence of HPV infection may differ across dimensions of sexual orientation, including sexual behavior (i.e., having sex with male or female partners) and sexual identity (i.e., considering oneself lesbian, bisexual, etc.). Such differences will have important implications for communicating information in our future intervention. We propose to address the existing research gaps by conducting secondary analyses of laboratory-verified HPV infection data among a population-based sample from the 2003-2012 National Health and Nutrition Examination Survey (NHANES). The proposed study, HPV Infection among Sexual Minority Women in the United States, will be the most comprehensive examination to date on HPV infection among sexual minority women, a hard-to-reach and understudied population at risk for health disparities. Aim 1 will provide robust data on the prevalence of genital HPV infection and differences across two dimensions of sexual orientation (i.e., sexual behavior and sexual identity). Such data are critical to women's knowledge about and perceived risk of HPV, which can in turn affect health behaviors. Aim 2 will identify determinants of genital HPV infection among sexual minority women, which will be key to our future intervention by identifying subgroups of sexual minority women at particularly high risk of HPV infection. Aim 3 will provide novel data on the prevalence of oral HPV infection among sexual minority women, which is important given the link between oral HPV infection and oral sex. Results from this study will provide needed robust data on HPV infection among sexual minority women, which will be a critical component of our future HPV and cervical cancer prevention intervention for this population.